Study On The Highway Alignment Parameter In Qinhai Gobi Desert

Since 1999, Qinghai expressway development has made brilliant achievements through more than 10 years. However, compared with other provinces, Qinghai expressway construction still serious lag behind and it affects on the local economic development and the improvement of people's living standard to a great extent. Based on the needs of the development of the economy and society, meanwhile implement central decision-making deployment and accelerate transportation infrastructure construction, the transport departmentin worked out "expressway network planning of Qinhai province" in 2008.The mileage of expressway which is being built and to be built is more than 5,000 km.The Construction task is very heavy.Up to now, there is little research on Gobi desert highway alignment in domestic. Therefore, it is significant to bring up the highway alignment parameters which suit the region environment of Qinghai gobi desert area.This paper maked a survey on natural geography, climate, population, ecological environment, economic development and traffic condition of Qinhai province and point out that the topography in Qinhai gobi desert area ups and downs gentle, the ecological environment is quite weak and most of the car on the roads are long-distance car which has little transverse interference.The actual speed of the car far outweigh the design speed.Compared with the expressway in other areas of our coutry,the expressway in Qinghai gobi desert area has its own charactoristics in numerous factors like regional environment,traffic compostion,driving behavior highway elignment and so on.Through the analysis of the highway elignment status in Qinhai gobi desert area,this paper summarized the characteristics of highway elignment in Qinhai gobi desert area,and point out that straight lines, circular curves, superelevation play an important role in highway elignment designing.According to the characteristics of Qinhai gobi desert area,the paper also point out the basis of determination of elignment parameter.At last,it made conclusions on the limit of straight length,curver radius and maximum superelevation and put forward recommendation suggestion on transverse slope design and plane and vertical combined design.